from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. An insane person.
  • n. A person who has an excessive enthusiasm or desire for something: a sports maniac.
  • n. A person who acts in a wildly irresponsible way: maniacs on the highway.
  • adj. Variant of maniacal.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. An insane person, especially one who suffers from a mania.
  • n. A fanatic, a person with an obsession.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Raving with madness; raging with disordered intellect; affected with mania; mad.
  • n. A raving lunatic; a madman.

from The Century Dictionary and Cyclopedia

  • Raving with madness; mad or crazy; insane.
  • n. One who raves with madness; a madman.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. an insane person
  • adj. wildly disordered
  • n. a person who has an obsession with or excessive enthusiasm for something


From Late Latin maniacus, maniacal, from Greek maniakos, from maniā, madness; see men-1 in Indo-European roots.
(American Heritage® Dictionary of the English Language, Fourth Edition)
Late Latin maniacus, from Ancient Greek μανιακός (maniakos), adjectival form of μανία (mania, "madness"). (Wiktionary)


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